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Condition

Hair Loss in Women & Hormones

Female hair loss almost always has a measurable driver — and in most women it's not genetic baldness, it's something correctable. The three most common patterns are diffuse telogen effluvium (a 2–4 month delayed shed after a stress, illness, sudden weight loss or pregnancy), androgenic thinning (widening part, shrinking ponytail — driven by sensitivity to androgens, often with PCOS or perimenopause), and thyroid- or iron-related shedding. A single blood panel resolves which pattern you're in and what to do.

Educational information from Her Form — reviewed for accuracy by our health specialists.
Not a substitute for personal medical advice. Optional 1:1 consults with Robyn, our consulting women's-health specialist, are available on request.

Common symptoms

  • •More hair in the brush, drain or pillow than 3–6 months ago
  • •Visibly thinner ponytail or widening part
  • •Thinning at the temples or crown
  • •Brittle, slow-growing hair and nails
  • •Increased facial or body hair alongside scalp thinning (androgenic)
  • •Eyebrow thinning on the outer third (thyroid)

What drives it

  • •Iron deficiency / low ferritin (the most common cause in menstruating women)
  • •Thyroid disease — hypo or hyperthyroid
  • •High androgens or androgen sensitivity (PCOS, perimenopause)
  • •Stress / illness / surgery / rapid weight loss 2–4 months prior (telogen effluvium)
  • •Vitamin D and B12 deficiency
  • •Postpartum hormonal shift

Testing approach

A targeted panel almost always finds the driver: ferritin (aim 70+ for hair, not just 'in range'), TSH with free T4 and free T3, total and free testosterone with SHBG and DHEA-S, vitamin D, B12 and HbA1c. Doing the full set in one draw saves the typical 'fix one thing, still shedding' cycle.

What to do next

  • ✓Test ferritin and a full thyroid panel before buying any supplement
  • ✓Replete iron if ferritin is under 70 — it can take 3–6 months to see regrowth
  • ✓Address androgen drivers if widening part or PCOS markers are present
  • ✓Protein 1.6 g/kg, consistent sleep, and avoid crash dieting
  • ✓Re-test the driving marker at 3–4 months to confirm it's moving

Frequently asked

Is hair loss in women always hormonal?

No — iron deficiency, post-illness telogen effluvium and crash dieting are the most common drivers in women under 40. Hormonal causes (thyroid, androgens, perimenopause) dominate from the late 30s on.

What ferritin level do I need for hair?

Most dermatologists aim for ferritin above 70 ng/mL specifically for hair regrowth — well above the standard 'normal' floor of around 15–30. 'In range' is not the same as optimal for hair.

Can perimenopause cause hair loss?

Yes. Falling estrogen and the relative rise in androgen sensitivity drive thinning at the part line and temples in the late 40s and 50s.

How long after I fix the cause will my hair grow back?

Hair grows about 1 cm a month. Once the driver is corrected, expect new growth within 3 months and visible density change by 6–9 months.

Will minoxidil work for women?

Topical minoxidil 5% (or oral low-dose minoxidil under prescription) works for most women, but only while you keep using it — and it won't outpace an unaddressed iron, thyroid or androgen problem.

Should I get a scalp biopsy?

Only if a dermatologist suspects scarring alopecia. For the diffuse shedding most women experience, a full blood panel is the right first step.

Can stress alone cause hair loss?

Yes — a significant stressor (illness, surgery, bereavement, major weight loss) can trigger telogen effluvium 2–4 months later. It usually self-resolves within 6–9 months once the trigger is gone.

References

References are provided for educational context only. Her Form is not affiliated with these organisations. Always interpret results with a qualified healthcare professional.

Information on this page is educational — wellness framing, not medical diagnosis. Always interpret results with a doctor who knows your history.